1. Field of the Invention
This invention relates to a case of a hydrogen absorption indirect heat exchanger having an indirect heat exchanger and a hydrogen absorbing alloy powder packed therein.
2. Description of the Related Art
Japanese Unexamined Patent Publication (Kokai) No. 11-30397 filed by the applicant of the present invention discloses a hydrogen absorption indirect heat exchanger that is produced by holding hydrogen absorbing alloy powder and an indirect heat exchanger in a sealed case, and stores hydrogen gas by utilizing the hydrogen absorbing/desorbing operation of a hydrogen absorbing alloy powder.
Since the indirect heat exchanger is substantially rectangular in this hydrogen absorption indirect heat exchanger, the sealed case has a structure in which each opening of a square cylindrical portion has a predetermined thickness and a substantially rectangular section is closed by a cover plate.
In the conventional sealed case having the structure in which each opening of the square cylindrical portion is closed by the cover plate, the sealed case must have a large thickness so as to withstand the increase of an internal pressure resulting from the expansion of hydrogen absorbing alloy powder when it absorbs hydrogen. In consequence, the weight becomes large and invites a problem when the heat exchanger is mounted to a vehicle or the like.
The present invention is completed in view of the problem described above, and aims at providing a case for a hydrogen absorption indirect heat exchanger, capable of reducing the weight while securing the case powder capacity.
The case for the hydrogen absorption indirect heat exchanger according to the present invention includes a square cylindrical portion each portion of which is integrally formed by die-casting or extrusion molding, and a cover plate for covering each opening of the square cylindrical portion. The corners of the square cylindrical portion and the center portion of each side, that are stress concentration portions, are shaped to a greater thickness than the thickness of other portions. Therefore, the present invention can provide a case capable of withstanding the increase of the internal pressure without increasing the thickness of all the portions as in the prior art, and can reduce the weight while the case powder capacity is secured.
The present invention may be more fully understood from the description of a preferred embodiment set forth below, together with the accompanying drawings.